More precise present syncing D3D

parsec-cloud · Dec 29, 2023 · a8f86fc · a8f86fc
1 parent 09ccf9d
commit a8f86fc
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Showing 3 changed files with 152 additions and 7 deletions.
diff --git a/src/windows/gfx/d3d11-ctx.c b/src/windows/gfx/d3d11-ctx.c
@@ -10,6 +10,7 @@ GFX_CTX_PROTOTYPES(_d3d11_)
 #include <dxgi1_5.h>
 
 #include "gfx/sync.h"
+#include "dxgi-sync.h"
 
 #define DXGI_FATAL(e) ( \
 	(e) == DXGI_ERROR_DEVICE_REMOVED || \
@@ -22,6 +23,8 @@ GFX_CTX_PROTOTYPES(_d3d11_)
 struct d3d11_ctx {
 	HWND hwnd;
 	struct sync sync;
+	struct dxgi_sync *dxgi_sync;
+	int64_t pcount;
 	uint32_t width;
 	uint32_t height;
 	ID3D11Device *device;
@@ -213,6 +216,7 @@ void mty_d3d11_ctx_destroy(struct gfx_ctx **gfx_ctx)
 
 	struct d3d11_ctx *ctx = (struct d3d11_ctx *) *gfx_ctx;
 
+	dxgi_sync_destroy(&ctx->dxgi_sync);
 	d3d11_ctx_free(ctx);
 
 	MTY_Free(ctx);
@@ -301,22 +305,30 @@ void mty_d3d11_ctx_set_sync_interval(struct gfx_ctx *gfx_ctx, uint32_t interval)
 	struct d3d11_ctx *ctx = (struct d3d11_ctx *) gfx_ctx;
 
 	sync_set_interval(&ctx->sync, interval);
+
+	if (interval > 100 && !ctx->dxgi_sync)
+		ctx->dxgi_sync = dxgi_sync_create(ctx->hwnd);
 }
 
 void mty_d3d11_ctx_present(struct gfx_ctx *gfx_ctx)
 {
 	struct d3d11_ctx *ctx = (struct d3d11_ctx *) gfx_ctx;
 
 	if (ctx->back_buffer) {
-		UINT interval = sync_next_interval(&ctx->sync);
+		int64_t interval = sync_next_interval(&ctx->sync);
 		UINT flags = interval > 0 ? 0 : DXGI_PRESENT_ALLOW_TEARING;
 
-		if (interval == 0 && !(ctx->flags & DXGI_SWAP_CHAIN_FLAG_ALLOW_TEARING)) {
-			interval = 1;
+		if (interval == 0 && !(ctx->flags & DXGI_SWAP_CHAIN_FLAG_ALLOW_TEARING))
 			flags = 0;
-		}
 
-		HRESULT e = IDXGISwapChain2_Present(ctx->swap_chain2, interval, flags);
+		int64_t elapsed = dxgi_sync_get_count(ctx->dxgi_sync) - ctx->pcount;
+
+		for (int64_t x = 0; x < interval - elapsed; x++)
+			dxgi_sync_wait(ctx->dxgi_sync, D3D11_CTX_WAIT);
+
+		HRESULT e = IDXGISwapChain2_Present(ctx->swap_chain2, 0, flags);
+
+		ctx->pcount = dxgi_sync_get_count(ctx->dxgi_sync);
 
 		ID3D11RenderTargetView_Release(ctx->back_buffer);
 		ctx->back_buffer = NULL;

diff --git a/src/windows/gfx/d3d12-ctx.c b/src/windows/gfx/d3d12-ctx.c
@@ -10,6 +10,7 @@ GFX_CTX_PROTOTYPES(_d3d12_)
 #include <dxgi1_4.h>
 
 #include "gfx/sync.h"
+#include "dxgi-sync.h"
 
 #define DXGI_FATAL(e) ( \
 	(e) == DXGI_ERROR_DEVICE_REMOVED || \
@@ -34,6 +35,8 @@ struct d3d12_ctx_buffer {
 struct d3d12_ctx {
 	HWND hwnd;
 	struct sync sync;
+	struct dxgi_sync *dxgi_sync;
+	int64_t pcount;
 	uint32_t width;
 	uint32_t height;
 
@@ -308,6 +311,7 @@ void mty_d3d12_ctx_destroy(struct gfx_ctx **gfx_ctx)
 
 	struct d3d12_ctx *ctx = (struct d3d12_ctx *) *gfx_ctx;
 
+	dxgi_sync_destroy(&ctx->dxgi_sync);
 	d3d12_core_free(&ctx->core);
 
 	MTY_Free(ctx);
@@ -406,6 +410,9 @@ void mty_d3d12_ctx_set_sync_interval(struct gfx_ctx *gfx_ctx, uint32_t interval)
 	struct d3d12_ctx *ctx = (struct d3d12_ctx *) gfx_ctx;
 
 	sync_set_interval(&ctx->sync, interval);
+
+	if (interval > 100 && !ctx->dxgi_sync)
+		ctx->dxgi_sync = dxgi_sync_create(ctx->hwnd);
 }
 
 void mty_d3d12_ctx_present(struct gfx_ctx *gfx_ctx)
@@ -441,10 +448,17 @@ void mty_d3d12_ctx_present(struct gfx_ctx *gfx_ctx)
 		ID3D12CommandQueue_ExecuteCommandLists(core->cq, 1, &cl);
 		ID3D12CommandList_Release(cl);
 
-		UINT interval = sync_next_interval(&ctx->sync);
+		int64_t interval = sync_next_interval(&ctx->sync);
 		UINT flags = interval > 0 ? 0 : DXGI_PRESENT_ALLOW_TEARING;
 
-		e = IDXGISwapChain3_Present(core->swap_chain3, interval, flags);
+		int64_t elapsed = dxgi_sync_get_count(ctx->dxgi_sync) - ctx->pcount;
+
+		for (int64_t x = 0; x < interval - elapsed; x++)
+			dxgi_sync_wait(ctx->dxgi_sync, D3D12_CTX_WAIT);
+
+		e = IDXGISwapChain3_Present(core->swap_chain3, 0, flags);
+
+		ctx->pcount = dxgi_sync_get_count(ctx->dxgi_sync);
 
 		if (DXGI_FATAL(e)) {
 			MTY_Log("'IDXGISwapChain3_Present' failed with HRESULT 0x%X", e);

diff --git a/src/windows/gfx/dxgi-sync.h b/src/windows/gfx/dxgi-sync.h
@@ -0,0 +1,119 @@
+// This Source Code Form is subject to the terms of the MIT License.
+// If a copy of the MIT License was not distributed with this file,
+// You can obtain one at https://spdx.org/licenses/MIT.html.
+
+struct dxgi_sync {
+	HANDLE event;
+	MTY_Thread *thread;
+	MTY_Atomic32 done;
+	MTY_Atomic64 count;
+};
+
+static void dxgi_sync_destroy(struct dxgi_sync **dxgi_sync)
+{
+	if (!dxgi_sync || !*dxgi_sync)
+		return;
+
+	struct dxgi_sync *ctx = *dxgi_sync;
+
+	MTY_Atomic32Set(&ctx->done, 1);
+	MTY_ThreadDestroy(&ctx->thread);
+
+	if (ctx->event)
+		CloseHandle(ctx->event);
+
+	MTY_Free(ctx);
+	*dxgi_sync = NULL;
+}
+
+static void *dxgi_sync_thread(void *opaque)
+{
+	struct dxgi_sync *ctx = opaque;
+
+	IDXGIFactory2 *factory2 = NULL;
+	IDXGIAdapter *adapter = NULL;
+	IDXGIOutput *output = NULL;
+
+	HRESULT e = CreateDXGIFactory2(0, &IID_IDXGIFactory2, &factory2);
+	if (e != S_OK) {
+		MTY_Log("'CreateDXGIFactory2' failed with HRESULT 0x%X", e);
+		goto except;
+	}
+
+	e = IDXGIFactory2_EnumAdapters(factory2, 0, &adapter);
+	if (e != S_OK) {
+		MTY_Log("'IDXGIFactory2_EnumAdapters' failed with HRESULT 0x%X", e);
+		goto except;
+	}
+
+	e = IDXGIAdapter_EnumOutputs(adapter, 0, &output);
+	if (e != S_OK) {
+		MTY_Log("'IDXGIAdapter_EnumOutputs' failed with HRESULT 0x%X", e);
+		goto except;
+	}
+
+	while (MTY_Atomic32Get(&ctx->done) == 0) {
+		e = IDXGIOutput_WaitForVBlank(output);
+		if (e != S_OK) {
+			MTY_Log("'IDXGIOutput_WaitForVBlank' failed with HRESULT 0x%X", e);
+			break;
+		}
+
+		MTY_Atomic64Add(&ctx->count, 1);
+
+		SetEvent(ctx->event);
+		ResetEvent(ctx->event);
+	}
+
+	except:
+
+	if (output)
+		IDXGIOutput_Release(output);
+
+	if (adapter)
+		IDXGIAdapter_Release(adapter);
+
+	if (factory2)
+		IDXGIFactory2_Release(factory2);
+
+	return NULL;
+}
+
+static struct dxgi_sync *dxgi_sync_create(HWND hwnd)
+{
+	struct dxgi_sync *ctx = MTY_Alloc(1, sizeof(struct dxgi_sync));
+
+	ctx->event = CreateEvent(NULL, TRUE, FALSE, NULL);
+	if (!ctx->event) {
+		MTY_Log("'CreateEvent' failed with error 0x%X", GetLastError());
+		goto except;
+	}
+
+	ctx->thread = MTY_ThreadCreate(dxgi_sync_thread, ctx);
+
+	except:
+
+	if (!ctx->event)
+		dxgi_sync_destroy(&ctx);
+
+	return ctx;
+}
+
+static int64_t dxgi_sync_get_count(struct dxgi_sync *ctx)
+{
+	if (!ctx)
+		return 0;
+
+	return MTY_Atomic64Get(&ctx->count);
+}
+
+static void dxgi_sync_wait(struct dxgi_sync *ctx, DWORD timeout)
+{
+	if (!ctx)
+		return;
+
+	DWORD e = WaitForSingleObjectEx(ctx->event, timeout, FALSE);
+
+	if (e != WAIT_OBJECT_0)
+		MTY_Log("'WaitForSingleObjectEx' failed with error 0x%X", e);
+}